1,226 research outputs found
Women's secure hospital services: national bed numbers and distribution.
A mapping exercise as part of a pathway study of women in secure psychiatric services in the England and Wales was conducted. It aimed to (i) establish the extent and range of secure service provision for women nationally and (ii) establish the present and future care needs and pathways of care of women mentally disordered offenders (MDO) currently in low, medium and enhanced medium secure care. The study identified 589 medium secure beds, 46 enhanced medium secure beds (WEMSS) and 990 low secure beds for women nationally. Of the 589 medium secure beds, the majority (309, 52%) are in the NHS and under half (280, 48%) are in the independent sector (IS). The distribution of low secure beds is in the opposite direction, the majority (745, 75%) being in the IS and 254 (25%) in the NHS. Medium secure provision for women has grown over the past decade, but comparative data for low secure provision are not available. Most women are now in single sex facilities although a small number of mixed sex units remain. The findings have implications for the future commissioning of secure services for women
Intra-hour cloud index forecasting with data assimilation
We introduce a computational framework to forecast cloud index (CI)fields for up to one hour on a spatial domain that covers a city. Such intra-hour CI forecasts are important to produce solar power forecasts of utility scale solar power and distributed rooftop solar. Our method combines a 2D advection model with cloud motion vectors (CMVs)derived from a mesoscale numerical weather prediction (NWP)model and sparse optical flow acting on successive, geostationary satellite images. We use ensemble data assimilation to combine these sources of cloud motion information based on the uncertainty of each data source. Our technique produces forecasts that have similar or lower root mean square error than reference techniques that use only optical flow, NWP CMV fields, or persistence. We describe how the method operates on three representative case studies and present results from 39 cloudy days
High-fidelity quantum logic gates using trapped-ion hyperfine qubits
We demonstrate laser-driven two-qubit and single-qubit logic gates with
fidelities 99.9(1)% and 99.9934(3)% respectively, significantly above the
approximately 99% minimum threshold level required for fault-tolerant quantum
computation, using qubits stored in hyperfine ground states of calcium-43 ions
held in a room-temperature trap. We study the speed/fidelity trade-off for the
two-qubit gate, for gate times between 3.8s and 520s, and develop a
theoretical error model which is consistent with the data and which allows us
to identify the principal technical sources of infidelity.Comment: 1 trap, 2 ions, 3 nines. Detailed write-up of arXiv:1406.5473
including single-qubit gate data als
Assessing the implementation of BIM – an information systems approach
Much attention has been paid to measuring the perceived benefits of Building Information Modelling (BIM). Yet despite an increase its adoption throughout the construction industry, important links between implementation, support and benefits are yet to be explored. We examine the constitutive elements of the BIM implementation process of two case studies implementing and using BIM: The first is a large urban regeneration project and the second is a healthcare project. A well-recognised model of system success is mobilised from the field of information systems (IS) to reveal that irrespective of project size and type, BIM benefits are confined to technically discrete productivity and efficiency gains when there is limited focus on the organisational aspects of BIM adoption. This paper focuses on the disconnections between organisational and project level BIM implementation using the DeLone and McLean Model as an analytical framework to systematically examine the benefits of BIM to each project in relation to the implementation approach employed. This study highlights the significance of these interdependencies and argues for a more comprehensive approach to BIM benefits capture that recognises this to usefully inform implementation strategy development
High-fidelity trapped-ion quantum logic using near-field microwaves
We demonstrate a two-qubit logic gate driven by near-field microwaves in a
room-temperature microfabricated ion trap. We measure a gate fidelity of
99.7(1)\%, which is above the minimum threshold required for fault-tolerant
quantum computing. The gate is applied directly to Ca "atomic clock"
qubits (coherence time ) using the microwave
magnetic field gradient produced by a trap electrode. We introduce a
dynamically-decoupled gate method, which stabilizes the qubits against
fluctuating a.c.\ Zeeman shifts and avoids the need to null the microwave
field
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Consequences of Biomarker Analysis on the Cost-Effectiveness of Cetuximab in Combination with FOLFIRI as a First-Line Treatment of Metastatic Colorectal Cancer: Personalised Medicine at Work
Background
Therapies may be more efficacious when targeting a patient subpopulation with specific attributes, thereby enhancing the cost-effectiveness of treatment. In the CRYSTAL study, patients with metastatic colorectal cancer (mCRC) were treated with cetuximab plus FOLFIRI or FOLFIRI alone until disease progression, unacceptable toxic effects or withdrawal of consent.
Objective
To determine if stratified use of cetuximab based on genetic biomarker detection improves cost-effectiveness.
Methods
We used individual patient data from CRYSTAL to compare the cost-effectiveness, cost per life-year (LY) and cost per quality-adjusted LY (QALY) gained of cetuximab plus FOLFIRI versus FOLFIRI alone in three cohorts of patients with mCRC: all randomised patients (intent-to-treat; ITT), tumours with no detectable mutations in codons 12 and 13 of exon 2 of the KRAS protein (‘KRAS wt’) and no detectable mutations in exons 2, 3 and 4 of KRAS and exons 2, 3 and 4 of NRAS (‘RAS wt’). Survival analysis was conducted using RStudio, and a cost-utility model was modified to allow comparison of the three cohorts.
Results
The deterministic base-case ICER (cost per QALY gained) was £130,929 in the ITT, £72,053 in the KRAS wt and £44,185 in the RAS wt cohorts for cetuximab plus FOLFIRI compared with FOLFIRI alone. At a £50,000 willingness-to-pay threshold, cetuximab plus FOLFIRI has a 2.8, 20 and 63% probability of being cost-effective for the ITT, KRAS wt and RAS wt cohorts, respectively, versus FOLFIRI alone.
Conclusion
Screening for mutations in both KRAS and NRAS may provide the most cost-effective approach to patient selection
Magnetic field stabilization system for atomic physics experiments
Atomic physics experiments commonly use millitesla-scale magnetic fields to
provide a quantization axis. As atomic transition frequencies depend on the
amplitude of this field, many experiments require a stable absolute field. Most
setups use electromagnets, which require a power supply stability not usually
met by commercially available units. We demonstrate stabilization of a field of
14.6 mT to 4.3 nT rms noise (0.29 ppm), compared to noise of 100 nT
without any stabilization. The rms noise is measured using a field-dependent
hyperfine transition in a single Ca ion held in a Paul trap at the
centre of the magnetic field coils. For the Ca "atomic clock" qubit
transition at 14.6 mT, which depends on the field only in second order, this
would yield a projected coherence time of many hours. Our system consists of a
feedback loop and a feedforward circuit that control the current through the
field coils and could easily be adapted to other field amplitudes, making it
suitable for other applications such as neutral atom traps.Comment: 6 pages, 5 figure
A microfabricated ion trap with integrated microwave circuitry
We describe the design, fabrication and testing of a surface-electrode ion
trap, which incorporates microwave waveguides, resonators and coupling elements
for the manipulation of trapped ion qubits using near-field microwaves. The
trap is optimised to give a large microwave field gradient to allow
state-dependent manipulation of the ions' motional degrees of freedom, the key
to multiqubit entanglement. The microwave field near the centre of the trap is
characterised by driving hyperfine transitions in a single laser-cooled 43Ca+
ion.Comment: 4 pages, 5 figure
Microwave control electrodes for scalable, parallel, single-qubit operations in a surface-electrode ion trap
We propose a surface ion trap design incorporating microwave control
electrodes for near-field single-qubit control. The electrodes are arranged so
as to provide arbitrary frequency, amplitude and polarization control of the
microwave field in one trap zone, while a similar set of electrodes is used to
null the residual microwave field in a neighbouring zone. The geometry is
chosen to reduce the residual field to the 0.5% level without nulling fields;
with nulling, the crosstalk may be kept close to the 0.01% level for realistic
microwave amplitude and phase drift. Using standard photolithography and
electroplating techniques, we have fabricated a proof-of-principle electrode
array with two trapping zones. We discuss requirements for the microwave drive
system and prospects for scalability to a large two-dimensional trap array.Comment: 8 pages, 6 figure
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